Headlight for road vehicles or the like



D. LELY, JR.

HEADLIGHT FOR ROAD VEHICLES OR THE LIKE.

APPLICATION FILEDIMAV II, 1921. I

1,431,964, Patented 0@t.17,1922.

Inventor Dirk Lely Jrz, 3 m -m Attorney.

Patented Oct. 17, 1922.

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A T HQE.

DIRK LELY, JR, OF EINDHOVEN, NETHERLANDS, ASSIGNOR TO COMPANY, OF NEW YORK, N. Y.

GENERAL ELECTRIC HEADLIGHT FOR ROAD VEHICLES OR THE LIKE.

Application filed may 11,

To all whom it may concern.

Be it known that I, DIRK LELY, Jr, a subject of the Queen of the Netherlands, residing at Eindhoven, in the Province of North Brabant, in the Kingdom of the Netherlands, have invented certain new and useful Improvements in Headlights for Road Vehicles or the like (for which I have filed an application in the Netherlands on May 1, 1920, Serial No. 14,690 Ned.), of which the following is a specification.

My invention relates to headlights designed to project upon the road in advance of a traveling vehicle, a non-glaring clear beam of light of wide lateral or horizontal spread and of limited verticalspread. and in addition thereto a diffused field of light in all forward directions. This object is. secured b the arrangement of a peculiar source 0' light in a peculiar reflector, as will appear from the following detail description with reference to the ac-r companying drawing, in which:

.. F1 1 is an end view of my improved lightlng unit, looking toward the opening of the reflector. i

Fig. 2 is a vertical axial section on line 2-2 of Fig. 1.

Fig. 3 is a horizontal axial section on line 33 of Fig: 1 and Fig. 4 is a view of the pfojection of a clear beam upon a vertical ane.

The reflector used in my system is pref erably a paraboloid 10, so thatlt he axial sections shown in Figs. 1 and 2 are pmbola-S. At the vertex, of this paraboloid is an opening for the reception of the socket 11 of an incandescent lamp 12, which is removably and exchangeably held in the socket. The incandescent filament of the lamp is a single closely wound spiral 13, which is in effect a long rectilinear source of light of small cross section. When the lamp is .in its proper position, the axis of the filament is horizontal, at right angles to the axis of the reflector, as indicated in F igs.. 1 and 3, and with its middle portion in the focus of the latter.

. The inner surface of the paraboloid reflector, which is clearly shown, particularly in Fig. 1, has only two specular bands of moderate width which are highly reflecting, one of these bands, 14, extending meridionally from the front edge of the paraboloid to'and beyond the vertex and 1921. Serial No. 468,736.

returning to the diametrically opposite part of the edge, in a horizontal direction, and the other band 15, extending in like manner in a vertical direction. The sectoral portions 16, of the inner face of the reflector between the {bands 14, 15, are etched or sand-blasted or otherwise frosted or made dull, to act as difli'users of the light incident thereon. These diffusing sectors are conspicuously marked in the drawing by appropriate dark, granular shading.

The effect of the construction described is as follows: The horizontal, specular, me-

ridional band 14 projects into the field of illumination an enlarged horizontal image of the axial extent of the rectilinear filament 13, while the vertical, specular, meridional band 15, projects in like manner an enlarged vertical image of the diameter of the rectilinear filament. Upon a vertical plane placed at any distance from the headlight at right angles to the axis of the reflector, the intercepted image has the form indicated in Fig. 4, which shows the wide lateral spread 13 13 of the beam due to the length of the filament and the horizontal, specular band 14, and the limited, narrow, vertical spread 13 of the beam due to the specular band 15. 1

Normally the headlight is mounted with the axis of the paraboloidal reflector in a horizontal osition, that is to say, parallel or slightly inclined to the even roadbed, and consequently the latter will be conspicuously lighted in front of the vehicle throughout a wid 'pgeerto the right and left of the running direction ofthe vehicle and the illumination will rise verticall}f to a ve y limited extent, so that a pedestrian in front diameter of the filament and the vertical of the vehicle or a driver of a vehicle run-.1

ning toward the headlight will experience no v are.

a In addition to this, the granular etched or sand-blasted sectors 16 produce a mild, widely diffused illumination as a background to the defined beam, whereby the contrast between this beam and its background is largely reduced, so that an accidental rise of the defined beam which may strike the eye of a pedestrian will'have less glaring effect than if the background to the defined beam were quite dark.

In addition to the production of a diffused light field by the frosted sectoral parts of the reflector, this frosting has also another and very important function. If the frosting were omitted, so that the whole inner surface of the reflector were specular, the sectoral portions would project into the field of illumination a variety of images of the spiral filament, variously inclined, all of which would merge into each other and produce an ill defined field of illumination. By restricting the specular surface of the reflector to the two bands 14, 15, a single, well defined image of the light source is projected, and the frosted sectoral surfaces are utilized for the production of a diffused background as hereinbefore described.

\Vhile the diffused field surrounding the defined beam is preferably produced by frosting the surfaces of the sectors between the specular bands, as herein described, other means having a like effect may be used as, for instance, the bulb of the incandescent lamp may be frosted in such parts which would otherwise allow the issue of undesirable defined beams.

Having now fully described my invention.

I claim and desire to secure by Letters Patent: v

1. A headlight comprising a paraboloidal reflector having two meridional, specular band surfaces at right angles to each other and the sectoral spaces between the bands frosted, with a rectilinear source of light with its axis intersecting the axis of the paraboloid' at the focus and extending within one of the bands across the width of same.

2. A headlight comprising a paraboloidal reflector having a horizontal and a vertical meridional, specular band surface and the intervening sectoral spaces frosted, with a sin le rectilinear spiral filament disposed with its axis horizontal across the focus and within the width of the horizontal band.

In witness whereof, I have hereunto signed my name in the presence of two subscribing witnesses.

DIRK LELY, JR. Witnesses:

ANTON DER NAGTEGAAL J r., CHRISTIAN VAN ENGELEN.

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